I have a WordPress web site running on my Windows Server 2008 R2 under IIS 7.0. I have embedded the code as given on the sample:

[video mp4="http://new.goodnewsjail.org/lbw.mp4" autoplay="true"]

Although the mp4 file indicated exists at that location (and can be accessed directly by putting in its URL in the web browser), it will not play in your player. The sample video oceans-clip.mp4 plays fine.

I have added the MIME types in IIS for .mp4 and .m4v to IIS as video/mpeg. I am not sure what else might be causing the video to not play. I see the video player, but nothing ever plays.